1. Field of the Invention
The present invention relates in general to a method and a system for automated synthesis of chemical products. More particularly, the present invention is concerned with an automated synthesis method and system which can automatically establish the optimum conditions for a synthesis reaction for producing a given chemical product to thereby control the synthesis reaction process such that the optimum reaction conditions can be realized.
2. Description of the Related Art
Heretofore, the synthesis of chemical products has been carried out through manual operations by an operator on the basis of empirically obtained knowledge and rules. By way of example, when an aimed chemical product is to be produced through the conventional synthesis procedure by adding a reagent to a reaction phase in which raw material compounds are in equilibrium with intermediate products to thereby cause the reagent to react with an intermediate product, the rate of addition of the reagent is usually determined by an operator intuitively on the basis of his or her experience, wherein such a control method is commonly adopted in which a predetermined amount of reagent is added successively at predetermined time intervals by taking into account the amount of supply of the raw material (starting) compounds. Consequently, enormous labor and time consumption are involved, in particular when a batch of different syntheses have to be dealt with. Besides, great difficulty has been encountered in attaining the desired purity and yield of the aimed or final product, not to speak of uniformity in the quality of the product.
For dealing with the problems mentioned above, there has already been proposed such an automated compound synthesizing system as shown in FIG. 6 of the accompanying drawings. This prior art system will briefly be described below.
Referring to FIG. 6, the automated synthesis system illustrated is composed of a synthesis processing apparatus 1 and a synthesis control apparatus 2, wherein the synthesis processing apparatus 1 is so arranged as to perform a series of process steps required for synthesizing an aimed product from the raw material (starting) compounds, while the synthesis control apparatus 2 serves to prepare the control information for controlling the operations of the synthesis processing apparatus 1 and at the same time supervise the states prevailing within the synthesis processing apparatus 1 for thereby reflecting the detected states onto the control.
The synthesis processing apparatus 1 comprises a reaction unit 11 for carrying out a synthesis reaction process, a raw material/reagent solvent supply unit 12 for supplying raw or starting materials, a reagent and a solvent to the reaction unit 11, a purification unit 13 for purifying a product resulting from the synthesis reaction process performed by the reaction unit 11, a freezing/drying unit 14 for lyophilizing the product purified by the purification unit 13, a washing solvent supply unit 15 for supplying a solvent for washing flow lines of the reaction unit 13 and the raw material/reagent/solvent supply unit 12, as occasion requires, a heating/cooling medium circulating unit 16 for heating or cooling the reaction unit 11 and the purification unit 13, an exhaust/drainage unit 17 for exhausting and draining the reaction unit 11 and the purification unit 13, an interface unit 18, and an electric power supply unit 19.
On the other hand, the synthesis control apparatus 2 comprises a computer or central processing unit (CPU) 21 for generating the control information for controlling sequentially the abovementioned individual units of the synthesis processing apparatus 1 in accordance with predetermined procedure and sequence, fetching various state signals detected by Sensors installed at the individual units of the synthesis processing apparatus 1 and executing a processing for reflecting the detected states onto the control, a memory device 22 connected to the CPU 21 for storing therein control programs, data and others, an operator input/output apparatus 23 including a keyboard and a cathode ray tube (CRT) display, and a hard copy printer 24.
The efficiency at which the aimed product is synthesized within the reaction unit 11 of the synthesis processing apparatus 1, i.e. the ratio of the amount of the product to the time required for the synthesis depends on the amount of the reagent as added and the rate of the addition, because the raw materials and the intermediate products are in the equilibrium state. In the automated synthesis system described above, however, the control information concerning the amount of addition of the reagent required for the control of the synthesis reaction has to be previously prepared logically through manual procedure and loaded in the synthesis control apparatus Z in the form of the control program and the control data. Further, the control information must be prepared separately for each of the formulae of chemical reactions involved in the synthesis, i.e. for each of different combinations of the raw material compounds, reagents and the aimed products.
As will be seen from the foregoing, the automated synthesis system described above also suffers from problems. First, the control information for controlling the synthesis reaction has to be created for each of the chemical reactions for synthesis. Further, in order to prepare such control information for the optimum reaction conditions which allows the synthesis reaction to take place at the maximum efficiency, retrieval of a data base including an accumulation of data obtained through lots of experiences is required, which means that the preparation of the control information is attended with a significant time consumption and a great burden to the operator Under the circumstances, it has been a common practice to prepare the control information rather intuitively by relying on the empirically acquired knowledge.